Status of Onchocerciasis transmission after more than a decade of mass drug administration for onchocerciasis and lymphatic filariasis elimination in central Nigeria: challenges in coordinating the stop MDA decision.
This study was undertaken in five onchocerciasis/lymphatic filariasis (LF) co-endemic local government areas (LGAs) in Plateau and Nasarawa, Nigeria. Annual MDA with ivermectin had been given for 17 years, 8 of which were in combination with albendazole. In 2008, assessments indicated that LF transm...
Published in: | PLoS Neglected Tropical Diseases |
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ftdoajarticles:oai:doaj.org/article:2dab0611976240dbba16c0f537f44ef0 2023-05-15T15:17:09+02:00 Status of Onchocerciasis transmission after more than a decade of mass drug administration for onchocerciasis and lymphatic filariasis elimination in central Nigeria: challenges in coordinating the stop MDA decision. Darin S Evans Kal Alphonsus Jon Umaru Abel Eigege Emmanuel Miri Hayward Mafuyai Carlos Gonzales-Peralta William Adamani Elias Pede Christopher Umbugadu Yisa Saka Bridget Okoeguale Frank O Richards 2014-09-01T00:00:00Z https://doi.org/10.1371/journal.pntd.0003113 https://doaj.org/article/2dab0611976240dbba16c0f537f44ef0 EN eng Public Library of Science (PLoS) http://europepmc.org/articles/PMC4169246?pdf=render https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0003113 https://doaj.org/article/2dab0611976240dbba16c0f537f44ef0 PLoS Neglected Tropical Diseases, Vol 8, Iss 9, p e3113 (2014) Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 article 2014 ftdoajarticles https://doi.org/10.1371/journal.pntd.0003113 2022-12-30T20:49:49Z This study was undertaken in five onchocerciasis/lymphatic filariasis (LF) co-endemic local government areas (LGAs) in Plateau and Nasarawa, Nigeria. Annual MDA with ivermectin had been given for 17 years, 8 of which were in combination with albendazole. In 2008, assessments indicated that LF transmission was interrupted, but that the MDA had to continue due to the uncertain status of onchocerciasis transmission. Accordingly, assessments to determine if ivermectin MDA for onchocerciasis could be stopped were conducted in 2009.We evaluated nodule, microfilarial (mf) skin snip, and antibody (IgG4 response to OV16) prevalence in adults and children in six sentinel sites where baseline data from the 1990s were available. We applied the 2001 WHO criteria for elimination of onchocerciasis that defined transmission interruption as an infection rate of <0.1% in children (using both skin snip and OV16 antibody) and a rate of infective (L3) blackflies of <0.05%.Among adult residents in sentinel sites, mean mf prevalence decreased by 99.37% from the 1991-1993 baseline of 42.95% (64/149) to 0.27% (2/739) in 2009 (p<0.001). The OV16 seropositivity of 3.52% (26/739) among this same group was over ten times the mf rate. No mf or nodules were detected in 4,451 children in sentinel sites and 'spot check' villages, allowing the exclusion of 0.1% infection rate with 95% confidence. Seven OV16 seropositives were detected, yielding a seroprevalence of 0.16% (0.32% upper 95%CI). No infections were detected in PCR testing of 1,568 Simulium damnosum s.l. flies obtained from capture sites around the six sentinel sites.Interruption of transmission of onchocerciasis in these five LGAs is highly likely, although the number of flies caught was insufficient to exclude 0.05% with 95% confidence (upper CI 0.23%). We suggest that ivermectin MDA could be stopped in these LGAs if similar results are seen in neighboring districts. Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic PLoS Neglected Tropical Diseases 8 9 e3113 |
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Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
spellingShingle |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 Darin S Evans Kal Alphonsus Jon Umaru Abel Eigege Emmanuel Miri Hayward Mafuyai Carlos Gonzales-Peralta William Adamani Elias Pede Christopher Umbugadu Yisa Saka Bridget Okoeguale Frank O Richards Status of Onchocerciasis transmission after more than a decade of mass drug administration for onchocerciasis and lymphatic filariasis elimination in central Nigeria: challenges in coordinating the stop MDA decision. |
topic_facet |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
description |
This study was undertaken in five onchocerciasis/lymphatic filariasis (LF) co-endemic local government areas (LGAs) in Plateau and Nasarawa, Nigeria. Annual MDA with ivermectin had been given for 17 years, 8 of which were in combination with albendazole. In 2008, assessments indicated that LF transmission was interrupted, but that the MDA had to continue due to the uncertain status of onchocerciasis transmission. Accordingly, assessments to determine if ivermectin MDA for onchocerciasis could be stopped were conducted in 2009.We evaluated nodule, microfilarial (mf) skin snip, and antibody (IgG4 response to OV16) prevalence in adults and children in six sentinel sites where baseline data from the 1990s were available. We applied the 2001 WHO criteria for elimination of onchocerciasis that defined transmission interruption as an infection rate of <0.1% in children (using both skin snip and OV16 antibody) and a rate of infective (L3) blackflies of <0.05%.Among adult residents in sentinel sites, mean mf prevalence decreased by 99.37% from the 1991-1993 baseline of 42.95% (64/149) to 0.27% (2/739) in 2009 (p<0.001). The OV16 seropositivity of 3.52% (26/739) among this same group was over ten times the mf rate. No mf or nodules were detected in 4,451 children in sentinel sites and 'spot check' villages, allowing the exclusion of 0.1% infection rate with 95% confidence. Seven OV16 seropositives were detected, yielding a seroprevalence of 0.16% (0.32% upper 95%CI). No infections were detected in PCR testing of 1,568 Simulium damnosum s.l. flies obtained from capture sites around the six sentinel sites.Interruption of transmission of onchocerciasis in these five LGAs is highly likely, although the number of flies caught was insufficient to exclude 0.05% with 95% confidence (upper CI 0.23%). We suggest that ivermectin MDA could be stopped in these LGAs if similar results are seen in neighboring districts. |
format |
Article in Journal/Newspaper |
author |
Darin S Evans Kal Alphonsus Jon Umaru Abel Eigege Emmanuel Miri Hayward Mafuyai Carlos Gonzales-Peralta William Adamani Elias Pede Christopher Umbugadu Yisa Saka Bridget Okoeguale Frank O Richards |
author_facet |
Darin S Evans Kal Alphonsus Jon Umaru Abel Eigege Emmanuel Miri Hayward Mafuyai Carlos Gonzales-Peralta William Adamani Elias Pede Christopher Umbugadu Yisa Saka Bridget Okoeguale Frank O Richards |
author_sort |
Darin S Evans |
title |
Status of Onchocerciasis transmission after more than a decade of mass drug administration for onchocerciasis and lymphatic filariasis elimination in central Nigeria: challenges in coordinating the stop MDA decision. |
title_short |
Status of Onchocerciasis transmission after more than a decade of mass drug administration for onchocerciasis and lymphatic filariasis elimination in central Nigeria: challenges in coordinating the stop MDA decision. |
title_full |
Status of Onchocerciasis transmission after more than a decade of mass drug administration for onchocerciasis and lymphatic filariasis elimination in central Nigeria: challenges in coordinating the stop MDA decision. |
title_fullStr |
Status of Onchocerciasis transmission after more than a decade of mass drug administration for onchocerciasis and lymphatic filariasis elimination in central Nigeria: challenges in coordinating the stop MDA decision. |
title_full_unstemmed |
Status of Onchocerciasis transmission after more than a decade of mass drug administration for onchocerciasis and lymphatic filariasis elimination in central Nigeria: challenges in coordinating the stop MDA decision. |
title_sort |
status of onchocerciasis transmission after more than a decade of mass drug administration for onchocerciasis and lymphatic filariasis elimination in central nigeria: challenges in coordinating the stop mda decision. |
publisher |
Public Library of Science (PLoS) |
publishDate |
2014 |
url |
https://doi.org/10.1371/journal.pntd.0003113 https://doaj.org/article/2dab0611976240dbba16c0f537f44ef0 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
PLoS Neglected Tropical Diseases, Vol 8, Iss 9, p e3113 (2014) |
op_relation |
http://europepmc.org/articles/PMC4169246?pdf=render https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0003113 https://doaj.org/article/2dab0611976240dbba16c0f537f44ef0 |
op_doi |
https://doi.org/10.1371/journal.pntd.0003113 |
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PLoS Neglected Tropical Diseases |
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8 |
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9 |
container_start_page |
e3113 |
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1766347416933498880 |